A major objective of this research is to obtain heterosteroids and related heterocyclic model compounds and examine same for ability to potentiate the activity for clinically-used antitumor agents. The ability of these compounds to form molecular complexes with the antitumor agents is also being investigated via the use of proton magnetic resonance and fluorescent spectroscopy in vitro. Another phase of the program is to prepare heterocycles and related glycosides for ability to alter membrane conformations which in turn may elicit an immune response from the host. BIBLIOGRAPHIC REFERENCES: E.A. Mawdsley, K.D. Berlin, R.W. Chesnut, an N.N. Durham, Synthesis and structure-activity relationships of heterocyclic compounds containing a trimethoxyarene function, J. Med. Chem., 19, In Press (1976). M.M. Hashem, K.D. Berlin, R.W. Chesnut, and N.N. Durham, Novel pyrazolo-, isoxazolo-, and thiazolosteroidal systems and model analogs containing dimethoxyaryl (or dihydroaryl) groups, and derivatives. Synthesis, spectral properties and biological activity, J. Med. Chem., 19, In Press (1976).